U.S. Navy(WASHINGTON) -- The No. 2 officer at U.S. Strategic Command, suspended from his position because of a criminal investigation, is suspected of using counterfeit gambling chips at a western Iowa casino. Stratcom commander Gen. Robert Kehler suspended Vice Adm. Tim Giardina from his duties as deputy commander on Sept. 3, according to Navy Capt. Pamela Kunze, a Stratcom spokeswoman.

She said Kehler had also recommended to Defense Secretary Chuck Hagel that Giardina be reassigned from his post. Kunze confirmed that Giardina was under investigation by the Navy Criminal Investigative Service (NCIS), but would not elaborate on what had prompted the investigation.

Giardina was unavailable for interview and had no comment, Kunze said.

Two U.S. officials familiar with the case said it involved "issues with gambling," and one of the officials added that misleading statements were also involved.

Kunze said NCIS began its investigation of Giardina in July after having been contacted by a non-Defense Department law enforcement agency. Based on the information from the NCIS's ongoing investigation Kehler decided on Sept. 3 that Giardina should be suspended.

Giardina remains Stratcom's deputy commander, but he is not carrying out the duties associated with the job that he has held since December 2011. His suspension was first reported by the Omaha World-Herald.

David Dales, a special agent in charge with the Iowa Division of Criminal Investigation (DCI), told ABC News that in June his agency began an investigation centered on the introduction of counterfeit poker chips in a poker game at the Horseshoe Council Bluffs Casino in Council Bluffs, Iowa. That city is located across the Missouri River from Omaha, Neb., which is near Stratcom's headquarters.

Dales said the use of counterfeit chips is "pretty rare" and constitutes "a Class D felony in the state of Iowa." Dale would not characterize the amount of chips used in the game, but described it as "a significant monetary amount."

He said his agency contacted StratCom "when we discovered the subject of the investigation that we had developed, and who that person was."

A source familiar with the case said Giardina was the subject of DCI's investigation

Dale said the investigation is still open and no charges have been brought in the case, though DCI's investigation is pretty much complete. The county attorney has decided to hold off on charges for the moment and DCI is fully cooperating with the investigation being conducted by NCIS, he said.

When asked about the Iowa DCI investigation, Kunze said it would be inappropriate to comment further.

"The matter is under investigation by NCIS at this point and time," she said.

Council Bluffs is home to three casinos that do the most gambling business in the state of Iowa. Horseshoe Council Bluffs Casino, run by Harrah's, is home to a greyhound race track and has table games and slot games inside a casino area.

Kunze said Kehler's recommendation said that "it is undetermined what if any additional actions will occur because the matter is under investigation" by NCIS.

A defense official said there is nothing to indicate there's been any compromise of Stratcom's mission or classified material in the matter involving Giardina.

Stratcom, based at Offutt Air Force Base in Bellevue, Neb., oversees the military's nuclear units and weapons.

Giardina was scheduled to leave Stratcom later this year and his successor, Lt. Gen. James Kowalski, had already been nominated by the White House.